Barkley attended the Trojans' final practice this season at Howard Jones Field but watched as freshman Max Wittek took the majority of snaps with the first-team offense. Freshman Cody Kessler also took some snaps under center.
USC coach Lane Kiffin said Barkley, who has been nursing a strained right shoulder for five weeks, will be evaluated again when the Trojans arrive in El Paso, Texas for their matchup with Georgia Tech on Dec. 31.
"We're going to look at it when we get down there and see if (Barkley) can practice," Kiffin said. "The one positive about (Barkley) not being here is (Wittek and Kessler) get more reps. It's going to help both of them."
Barkley has been sidelined since suffering the injury Nov. 17 in USC's loss to rival UCLA. A senior and one-time Heisman Trophy contender, Barkley has stated publicly that he hopes to end his collegiate career by playing in the Sun Bowl.
USC will hold its first practice in El Paso on Wednesday.
Wittek made his first career start in USC's regular season-ending loss to Notre Dame, completing 14 of 23 passes for 186 yards, one touchdown and two interceptions.